Evaluation of Vascular Proliferation in Molecular Subtypes of Breast Cancer

Background: Angiogenesis plays a pivotal role in tumor development. Although microvessel density (MVD) is the most common method used for evaluation of angiogenesis, it has several limitations. Our aim was to evaluate MVD and microvessel proliferation (MVP) in a series of invasive breast carcinomas and analyze whether angiogenesis is influenced by the molecular phenotype of each tumor. Materials and Methods: We examined vascular proliferation using double immunohistochemistry (CD34/Ki67) in a series of 54 invasive breast carcinomas and compared the results with standard MVD, molecular subtypes and other classical parameters. Results: Increased MVD and MVP values were recorded in basal-like subtype, but only the MVP value reached significance among this group of patients (p=0.0001). For all cases combined, increased MVP was significantly correlated with negative estrogen receptor (ER) status (p=0.010) and higher histological grade (p=0.002). Conclusion: MVP more accurately reflects the state of angiogenesis in breast cancer, compared with standard MVD. Vascular proliferation was associated with aggressive tumor features, indicating its contribution to tumor progression. The strong association between vascular proliferation and basal-like tumors suggests that this marker can be used for stratification of patients who might benefit from therapies targeting angiogenesis.